The enormous ‘El Gordo’ cluster of galaxies suggests that dark matter is colliding with itself

A view of space with blue and pink hazes overlaying lots of stars and galaxies.

Strange behavior in a huge cluster of merging galaxies could be explained if dark matter, the universe’s most mysterious stuff, can collide with itself. However, the most favored model of cosmology at the moment is the Cold Dark Matter (CDM) model – and it suggests that dark matter, which is effectively invisible because it does … Read more